Welcome to TW! I believe the 4.5" backspace should stick out more. I also have a 3" lift in front and have the same wheels in 16x8 with 4.5" bs with 285/75/16 KM2's and i love them. In my opinion, they stick out just the right amount. I just had to cut a small piece of plastic inside the fender well and now have no rubbing. Not sure if you can really tell how much they stick out in this picture, but it's the only one I have right now. I'll try to remember to take a couple more so you can see better.

The bolt pattern is 6x5.5 right? And I have to buy lug nuts seperatly ?

I don't know much about the lug nut options, but when I got my procomp 7089s I ordered lug nuts with them and it came with spline drive (I think thats what theyre called) lug nuts. Anyway, there's an adapter key you have to attach to your lug wrench to get the lugs off and it's a pain to use because the adapter gets stuck on the lugs and I had to hit it with the wrench to release it. If i were you, I would get non-locking lug nuts so that's not a problem (if that's an option) just my .02